package codingInterview.leetcode.editor.cn;

//给你二叉树的根节点 root 和一个整数目标和 targetSum ，找出所有 从根节点到叶子节点 路径总和等于给定目标和的路径。 
//
// 叶子节点 是指没有子节点的节点。 
//
// 
//
// 示例 1： 
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// 
//
// 
//输入：root = [5,4,8,11,null,13,4,7,2,null,null,5,1], targetSum = 22
//输出：[[5,4,11,2],[5,8,4,5]]
// 
//
// 示例 2： 
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// 
//
// 
//输入：root = [1,2,3], targetSum = 5
//输出：[]
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// 示例 3： 
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//输入：root = [1,2], targetSum = 0
//输出：[]
// 
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// 
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// 提示： 
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// 
// 树中节点总数在范围 [0, 5000] 内 
// -1000 <= Node.val <= 1000 
// -1000 <= targetSum <= 1000 
// 
//
// 注意：本题与主站 113 题相同：https://leetcode-cn.com/problems/path-sum-ii/ 
// Related Topics 树 深度优先搜索 回溯 二叉树 👍 301 👎 0

import java.util.ArrayList;
import java.util.List;

//Java：剑指 Offer 34 - 二叉树中和为某一值的路径
public class ErChaShuZhongHeWeiMouYiZhiDeLuJingLcof{
    public static void main(String[] args) {
                Solution solution = new ErChaShuZhongHeWeiMouYiZhiDeLuJingLcof().new Solution();
        // TO TEST
    }
    
    //leetcode submit region begin(Prohibit modification and deletion)
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    List<List<Integer>> result = new ArrayList<>();
    List<TreeNode> history = new ArrayList<>();
    int target=0;
    int sum=0;
    public List<List<Integer>> pathSum(TreeNode root, int target) {
        this.target = target;
        dfs(root);
        return result;
    }

    private void dfs(TreeNode root){
        if(root == null) return;
        history.add(root);
        sum+=root.val;
        if(root.left == null && root.right ==null && sum==target){
            result.add(printPath(history));
        }
        dfs(root.left);
        dfs(root.right);
        history.remove(history.size()-1);
        sum-=root.val;
    }

    private List<Integer> printPath(List<TreeNode> list){
        List<Integer> res = new ArrayList<>();
        for (TreeNode node : list) {
            res.add(node.val);
        }
        return res;
    }
}
//leetcode submit region end(Prohibit modification and deletion)
public class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;
    TreeNode() {}
    TreeNode(int val) { this.val = val; }
    TreeNode(int val, TreeNode left, TreeNode right) {
        this.val = val;
        this.left = left;
        this.right = right;
    }
}
}
